Typically, gas turbine engines include a compressor for compressing air, a combustor for mixing the compressed air with fuel and igniting the mixture, and a turbine blade assembly for producing power. Combustors often operate at high temperatures that may exceed 2,500 degrees Fahrenheit. Typical turbine combustor configurations expose turbine blade assemblies to these high temperatures. As a result, turbine blades must be made of materials capable of withstanding such high temperatures. In addition, turbine blades often contain cooling systems for prolonging the life of the blades and reducing the likelihood of failure as a result of excessive temperatures.
Typically, turbine blades are formed from a root portion and a platform at one end and an elongated portion forming a blade that extends outwardly from the platform. The blade is ordinarily composed of a tip opposite the root section, a leading edge, and a trailing edge. The inner aspects of most turbine blades typically contain an intricate maze of cooling channels forming a cooling system. The cooling channels in the blades receive air from the compressor of the turbine engine and pass the air through the blade. The cooling channels often include multiple flow paths that are designed to maintain all aspects of the turbine blade at a relatively uniform temperature. However, centrifugal forces and air flow at boundary layers often prevent some areas of the turbine blade from being adequately cooled, which results in the formation of localized hot spots. Localized hot spots, depending on their location, can reduce the useful life of a turbine blade and can damage a turbine blade to an extent necessitating replacement of the blade.
Conventional turbine blades often include a plurality of holes in the leading edges that form showerheads for exhausting cooling fluids from the internal cooling systems to be used as film cooling fluids on the outer surfaces of the turbine blades. Often times, the cooling fluids flowing through these holes are not regulated. Instead, cooling fluids are often passed through the showerhead at too high of a flow rate, which create turbulence in boundary layers of cooling fluids at the outer surfaces of the turbine blades. This turbulence reduces the effectiveness of downstream film cooling. In addition, the cooling fluids are often discharged at dissimilar pressures, which further reduces the downstream film cooling effectiveness. While these conventional systems reduce the temperature of leading edges of turbine blades, a need exist for an improved leading edge cooling system capable of operating more efficiently.